<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>缺省参数</title>
    <style>
        *{margin: 0;padding: 0;list-style-type: none;}
    </style>
</head>
<body>
    <script>
        function fn(a,b = 0,c = 0){
            console.log()
        }
        fn(10)
    </script>
</body>
</html>